package test;

import java.awt.*;

/**
 * @author BianWenKai
 * @DATE 2021/9/6 - 11:07
 **/
public class Child extends Person {
    public String grade;
    static int num = 1;
    public static void main(String[] args) {
        Person person = new Child();
        System.out.println(person.age);
        char c =65;
        System.out.println(c);
        String s1 = "runoob";
        String s2 = "runoob";
        System.out.println(s1 == s2);
        System.out.println("===================");
        //空引用可用于访问静态变量或方法
        Child child = null;
        System.out.println(child.num);
        child.test();
        System.out.println("===================");
        int a1 = 5;
        double a2 = (float)a1;
        System.out.println(a2);

    }

    public static void test(){
        System.out.println("test");
    }
}
